In recordings from the lateral geniculate nucleus and striate cortex of monkey and cat, we intend to examine the nature of spatial processing by the visual system. Specifically, we shall examine the spatial frequency and temporal frequency tuning of LGN and cortical cells to luminance-based and color-based patterns. We will also examine the extent to which we can predict the responses of a cell to various other patterns (bars, square waves, combinations of 2 frequencies) from its spatial sine wave sensitivity function.